1. Field of the Invention
The present invention relates generally to an adjustable compression arm band and, more specifically, to an arm band constructed to be worn by persons suffering from symptoms of carpal tunnel syndrome.
2. Reference to Patent Application
Reference is made to patent application Ser. No. 07/976,646 filed Nov. 13, 1992 now U.S. Pat. No. 5,295,951 entitled: Device and Method for Treating Tennis Elbow by the present inventor.
3. Prior Art
Carpal tunnel syndrome is the most common entrapment neuropathy of the upper extremity. Because of increased awareness on the part of physicians and the public, the syndrome is now recognized and managed by primary care physicians and occupational health workers as well as hand surgeons. The term "syndrome" means a combination of signs and/or symptoms that form a distinct clinical picture indicative of a particular disorder. Thus, the term "carpal tunnel syndrome" as used herein refers to a particular complex of symptoms and not to a particular etiology. The carpal tunnel represents a canal having affixed space with a finite volume. Any increase in the volume of the contents of the carpal tunnel will correspondingly raise the pressure within the canal. A number of conditions such as obesity or pregnancy can increase the contents or decrease the size of the carpal tunnel and thereby compress the median nerve. Anomalous muscles and osseous and foreign bodies in the carpal tunnel may also compress the median nerve. Similarly, any condition that produces edema in the hand and wrist may cause or accentuate carpal tunnel compression. A non-specific thickening of the tenosynovium appears to be the most common cause of carpal tunnel syndrome. This condition is characterized by thickening of the tenosynovium, which increases the volume of the structures within the carpal tunnel. Tenosynovitus is usually considered nonspecific but may be associated with gout or rheumatoid arthritis or, in fact, many other conditions.
Clinically, a careful physical examination with objective testing are important steps in evaluating the compressive nerve lesions The median nerve innervates the thumb, index and long fingers and the radial side of the ring finger. The symptoms of carpal tunnel syndrome may occur in any of these fingers, although most frequently hyperestheia, paraesthesia or hypoesthesia is observed in the middle (long) finger. Such symptoms are indicative of compression of the median nerve although not necessarily in the carpal tunnel. The wrist flexion test, or Phalen's test, is positive in more than 60% of patients and is considered strong evidence for carpal tunnel syndrome. The test is accomplished by having the patient hold the wrist in a maximally flexed posture. This increases the pressure on the median nerve and reproduces the symptoms of paraesthesia in the digits of the median nerve distribution.
While the severity of symptoms will normally determine the method of treating carpal tunnel syndrome, the treatment can be roughly divided into surgical and non-surgical. If the pain is not great or if the symptoms are of very brief duration, non surgical intervention is usually attempted. Such non-surgical intervention may include splinting to immobilize the wrist and/or the injection of an anti-inflammatory such a cortisone into the tendons passing through the carpal tunnel to reduce the inflammation. Such splinting restricts the use of the affected hand and care must be taken to inject directly into the median nerve. It would be desirable to provide a non surgical method of treating the symptoms of carpal tunnel syndrome which does not require the immobilization of the wrist or injection of steroid. Surprisingly, the present invention has found that a transaxial compression band when applied to the forearm is useful for treating the symptoms of carpal tunnel syndrome with only minimal impairment of the normal circulation up and down the arm.